This invention relates in general to filter constructions and in particular to a new and useful filter and housing particularly for vehicle compartments and other spaces which are closed to the outside.
The room in the inside of vehicles for handling the exchange of used filter elements is very limited. This is particularly true for the opening of the filter housing in order to make the filter elements accessible.
Normally, the openings of filter housings are closed with covers, which are then opened and removed. Suitable constructions can be found for the covers and their gastight closures.
A known filter for cleaning air for rooms closed to the outside in its housing comprises several openings tightly sealed by covers for removal of filter units. Each cover is movably attached to the housing via two straps which are hinged both at the cover and at the housing. A closing rod, with a longitudinal slot which is tiltable and slidable is located between the straps in their support at the housing. The free end of the closing rod engages in its closing position with an ear attached to the housing. The closing rod carries a pressing screw for pressing the cover.
For opening, after release of the pressing screw, the closing rod is slid out of the ear and together with the straps the cover is turned up. The closure occurs in the opposite sequence. There are difficulties in applying this to limited space because of the sideway protrusion of the closure mechanism. Cover and closure remain with the housing and limit the accessibility during the change of the filter units. An immediate removal of loaded filter units into a protective bag is not possible. (German Pat. No. 12 81 267).
A known rapid closure for a releasable connection of a removable housing part, especially of a maintenance cover, with a stationary housing part comprises at least a gripping lever tiltably supported at one of the housing parts and one spring element prestressed by the lever and engaging the other housing part. This spring element is a leaf spring in the form of a rectangularly warped, two armed spiral spring. One arm is hung from its side on the stationary housing part toward the outside protruding, support strap, such that the end of the arm rests on the edge of the removable housing part and can press against it. The other arm which extends from the housing surface toward the outside has a connecting strap, which is hinged at the gripping lever and supported at the removable housing part. A disadvantage is that an open-position freely movable linked connection of gripping lever, connecting strap and spiral spring; the proper positioning and pressing of the closure requires both attention and the use of both hands. Operation in limited space is very difficult. For the hanging and disengaging of the spiral spring is necessary a larger free space on the side, which does not allow the arrangement of several covers in close spacing. (German Patent Application Disclosure DE-OS No. 25 34 612).